Arithmetic ability is critical for daily life, academic achievement, career development, and future economic success. Individual differences in arithmetic skills among children and adolescents are related to variations in brain structures. Most existing studies have used hypothesis-driven region of interest analysis. To identify distributed brain…

The choice of cortisol sampling times in early childhood studies varies widely. Given that recommendations on sampling protocols are largely based on adults, the present study aimed to broaden current knowledge by examining how reliably cortisol measures obtained at different daytimes would reveal between-individual differences in toddlers'…

The present study examined individual differences in the development of sustained attention across toddlerhood, as well as how these individual differences related to the development of language and sleep. Toddlers (N = 314; 54% male) were assessed at 30, 36, and 42 months using multiple measures of attention, a standardized language assessment,…

How does language shape mathematical development? In this article, we consider this question by reviewing findings from cross-sectional and longitudinal research. In this literature, we find that differences in the structures of languages and individual variations in language ability are associated with mathematical performance in both obvious and…

There is no relationship more vital than the one a child shares with their primary caregivers early in development. Yet many children worldwide are raised in settings that lack the warmth, connection, and stimulation provided by a responsive primary caregiver. In this study, we used data from the Bucharest Early Intervention Project (BEIP), a…

Throughout the life span, we are capable of representing quantities in the absence of language, or nonsymbolically. Additionally, over the course of development, we learn many symbolic measurement systems for representing quantities such as time and number. Despite substantial evidence of a relation between the acquisition of symbolic and…

The current study investigated the development of children's performance on tasks that have been suggested to underlie early mathematics skills, including measures of cardinality, ordinality, and intelligence. Eighty-seven children were tested in their first (T1) and second (T2) school year (at ages 5 and 6). Children's performance on all tasks…

We investigated the association between individual differences in metaphor understanding and Theory of Mind (ToM) in typically developing children. We distinguished between two types of metaphors and created a Physical and Mental Metaphors task, echoing a similar distinction for ToM. Nine-year-olds scored lower than older age-groups in ToM as well…

Children's own spontaneous mathematical activities are crucial for their mathematical development. Mathematical thinking and learning does not only occur in explicitly mathematical situations, such as the classroom. Those children with higher tendencies to recognize and use mathematical aspects of their everyday surroundings, both within the…

In recent years, an increased interest in the importance of children's ability to regulate emotions in socially adaptive ways has driven considerable research on the development of emotion regulation. A widely studied emotion regulation strategy known as "expressive suppression" (ES), in which a person attempts to conceal…

Research suggests that individual differences in math abilities correlate with approximate representations of quantity that are supported by a primitive Approximate Number System (ANS). However, relatively little research has addressed the direction of this association in early childhood. Here we examined the development of the ANS and math…

This study explored developmental and individual differences in intellectual humility (IH) among 127 children ages 6-8. IH was operationalized as children's assessment of their knowledge and willingness to delegate scientific questions to experts. Children completed measures of IH, theory of mind, motivational framework, and intelligence, and…

The association between academic self-concept and achievement is assumed to be reciprocal. Typically, the association is analyzed by variants of the classical cross-lagged panel model. Results with more recently developed methodological approaches, for example, the random intercept cross-lagged panel model, its continuous-time implementation, and…

Eye tracking research has shown that infants develop a repertoire of attentional capacities during the first year. The majority of studies examining the early development of attention comes from Western, high-resource countries. We examined visual attention in a heterogeneous sample of infants in rural Malawi (N = 312-376, depending on analysis).…

Narrative production draws upon linguistic, cognitive and pragmatic skills, and is subject to substantial individual differences. This study aimed to characterise the development of narrative production in late childhood and to assess whether children's cumulative experience of reading fiction is associated with individual differences in narrative…